Blue Angel

Can anyone explain the real differences between the 555R Drag Radials and the 555RII Road Race tires? Is the construction really different? I've read several people claim they noticed little difference, if any, between the two on their C5Zs. What about the tread compound?

I also read that the 555RII came to be when Nitto discovered road racers using the 555R Drag Radials on the road course. This sort-of makes sense to me as Nitto claims the RII has very stiff sidewalls and in reality they are very compliant, making me wonder if there's a difference at all...

AlwaysInBoost

all the research I did prior to purchasing my RII's showed the only difference between their DR and RR tire was an extra belt in the sidewall for stiffness.

rustyguns

good to know...so only difference would be in high speed cornering

jaybar

I run the 555R drag radial front and back on my Backdraft 427SC. The main reason was that I couldn't get the size I needed in the 555II. A friend with the same setup called Nitto tech support and was told it would be fine to run the DR's on a light car 2,550 car on a road course, but suggested adding a few lb's of air to compensate for the softer sidewalls.

ls1_alex

Try the NT01 nitto tire.. Once they get a small warmup they are as sticky as the drag radials, and work great when road racing.

beerkat

I run 315/35x17 all around on my car.

ls1_alex

Yeah and no issue driving em on the street either.

Blue Angel

Thanks guys!

The reason I'm asking is I will be stretching the rear 305's over the max width rim (12"), so I wondered what the difference would be in turn in/steering feedback/cornering grip between the two.

The way the car sits right now with the 305RII on the stock 10.5" rear wheel there is a disconcerting loss of steering feel/feedback from the rear of the car (compared to the OEM GoodYear 295 Supercars). I think this effect is two-fold; one, the RII has a softer sidewall than the Supercar tire, and two, the RII's sidewall is noticeably "rounded" on this wheel width, possibly contributing to sidewall flex under load.

Stretching the 305 over a 12" wheel will hopefully restore the steering feedback to the rear of the car.

Any idea on how to get a hold of Nitto Tech Support? I sent a question in through their website asking about the difference in lateral load deflection between the two tires on 12" wheels, but I seriously doubt I'll get a response, let alone any useful information...